Tree of life
A clade (from Ancient Greek: κλάδος, klados, "branch"), also known as monophyletic group, is a group of s that consists of a and all its , and represents a single "branch" on the " ".From The blue and red subgroups (below) are s, or (complete) groups; each shows its common ancestor 'stem' at the bottom of the subgroup 'branch'. The green subgroup is not a clade. It is an incomplete clade because it excludes the blue branch even though it has also descended from the common ancestor stem at the bottom of the green branch. The green box (central) could represent an , a group united by conservative anatomical and physiological traits rather than phylogeny. The green subgroup together with the blue one forms a clade again.From A homoplasy is a characteristic that is shared by two or more taxa due to some cause other than common ancestry. The two main types of homoplasy are convergence (evolution of the "same" character in at least two distinct lineages) and reversion (the return to an ancestral character state).Cladogram Convergent evolution From * * * ** — ( ), , (or cryptomonads), and ** (or ) — , e, e, and s *** (Glaucocystophyta) – a small group of freshwater single-celled algaeTheir chloroplasts, called cyanelles, have a layer, making them more similar to cyanobacteria than those of the remaining Archaeplastida. *** (Rhodophyta) – red algae. Most are seaweeds *** (Viridiplantae; Chlorobionta; Chlorobiota) – green algae **** (Mesostigmata) **** – green algae (part) **** – green algae (part) **** – green algae (part) **** (Charophyceae) – green algae (part) and land plants ***** – stoneworts and land plants ****** (Charophytae) – stoneworts ****** (Cormophyta; Embryophyta) – land plants (embryophytes) ******* ******* ******* ******* Chlorobionta ******** ******* ******** ******** (stoneworts) ******** ? ******** ******** ******** (land plants) ********* (liverworts) ********* (mosses) ********* (hornworts) ********* † ********* † ********* (vascular plants) ********** Non-seed-bearing plants *********** †'' '' *********** † *********** † *********** *********** † *********** (Fern) *********** † ********** Superdivision *********** † *********** *********** ** — Various protozoa ** — most lobose s and s ** — , , and various other protozoa ** — , , , *** **** **** *** **** (= Mesomycetozoea) **** ***** ***** **** ***** ***** ****** ****** (animals) ******* ******* ******** ******** ******** ******** † ******** ********* †'' '' ********* ********* † ********* ********** *********** }} (mollusca) *********** }} (arthropods) ********** }} (vertebrates, starfish, acorn worms) Mollusca }} * * * * * * † * * * ** —An ancient lineage of molluscs with cap-like shells **† — fossils; probable ancestors of bivalves **† — fossils; snail-like organisms such as ** — All the s and s including , s, , s, s, ** — s, s, s, s, s ** — chitons ** a — , , , , ** — tusk shells ** — worm-like organisms Arthropods }} * ** *** **** ***** †'' '' ***** † ***** †'' '' ***** †'' '' ***** † ***** †'' '' **** † ***** † – trilobites **** ***** – etc. ***** – blind crustaceans ***** – horseshoe shrimp ***** – s, , , etc. ***** – seed shrimp ***** – s, s, , etc. **** ***** – s, ns, etc. ***** – sea spiders **** ***** – s ***** – s ***** – sister group to millipedes ***** – resemble centipedes **** ***** – , etc. ***** – insects Vertebrates }} *" " ** (acorn worms) **† a ** (starfish) *† * (vertebrates) ** *** ** *** *** † *** †'' '' *** †'' '' ** † ? *** ****'' '' **** or ( s and other jawless fishes) **** (vertebrates with jaws) ***** † (extinct armoured fishes) ***** (cartilaginous fishes) ***** † (extinct spiny "sharks") ***** Superclass (bony vertebrates) ****** (ray-finned bony fishes) ****** (lobe-finned fishes, including the tetrapods) ****** (amphibians, some ancestral to the )- now a paraphyletic group ****** }} (reptiles and birds) ****** }} (reptile-like mammals) Reptiles Mammals }} (reptile-like mammals) (Pelycosaur) *''† '' *''† ? *† **† **† **† ? * ** † ** † ** † ** *** † '' ***†'' '' *** †'' '' *** †'' '' *** **** †' ' (Dimetrodon) **** (upright) ***** †'' ? ***** † ***** Eutherapsida ****** † ******* † ia ******* † ****** ******* † ia ******** † ******** † ia (Lystrosaurus) ******* ia ******** † ******** ia ********* † ********* ia ********** (mammals) *********** ************ ************* *********** ************ ************* ************** *************** **************** }} **************** }} Marsupialia From : }} * ** (93 species) *** : opossums ** (seven species) *** : s * ** (one species) *** : ** † (''incertae sedis) ** (75 species) *** † : *** : es, s, s, , and relatives *** : ** (two species) *** : s ** (24 species) *** : *** †Chaeropodidae: s *** : s and allies ** (137 species) *** **** : s **** : s **** † : **** † : **** † : *** **** : and **** : s **** † tidae: s **** : , , , , , **** : s and es **** : and relatives **** : *** **** : s, , and relatives **** : s, rat kangaroos, s **** : Placentalia From : }} * ( , , and ) ** ( ) ** ( and ) * ( , , , , , and ) ** *** ( and ) *** ( ) *** ( ) ** *** ( ) *** ( , , and ) **** ( ) **** ( and ) * ** ( , , , , , , , , and ) *** ( , s, , , and s) *** ( ) *** ( : , , , , , , etc.) *** ( : , , , , and ) *** ( , , , , , , etc.) **** ( ) **** ( : , , , , , etc.) ** ( s, , , , , and s) *** **** ***** ( , , and ) ***** ia ( s: , , , , , etc.) *** **** ( s) **** ***** ( ) ***** (primates: , , , , , etc.) ****** : lemurs, galagos and lorisids ******* ******** ********* : dwarf lemurs and mouse-lemurs (34 species) ********* : aye-aye (one species) ********* : ring-tailed lemur and allies (21 species) ********* : sportive lemurs (26 species) ********* : woolly lemurs and allies (19 species) ******** ********* : lorisids (14 species) ********* : galagos (19 species) ****** : tarsiers, monkeys and apes ******* ******** : tarsiers (11 species) ******* (or Anthropoidea) ******** Parvorder : New World monkeys ********* : marmosets and tamarins (42 species) ********* : capuchins and squirrel monkeys (14 species) ********* : night or owl monkeys (douroucoulis) (11 species) ********* : titis, sakis and uakaris (43 species) ********* : howler, spider, woolly spider and woolly monkeys (29 species) ******** ********* ********** : Old World monkeys (138 species) ********* ********** : gibbons or "lesser apes" (18 species) ********** : great apes, including humans (8 species) *********** : orangutans *********** : hominines ************ : gorillas ************ : hominins ************* : chimpanzees ************* : homininans ************** : man References Category:Tree of life